I will use this post to collect some of the problems we are hearing about with Windows 7 SP1 and Windows 2008 R2 SP1. Right now, there is no urgent reason to install this service pack and it should be tested first.

A few areas to watch:

- Whitelisting / Blacklisting: Whitelisting software may not have checksums yet to verify all the files that are modified by the service pack. Same for anti-virus: Some anti virus products monitor system files for changes and may sound an alert or block the installation of SP 1

- Firewalls: Third party firewalls may find that some of the low level hooks they use have changed.

- Disk Encryption: In particular full disk encryption that modifies the boot process may find that some of the changes it did are undone by the SP install

- Custom hardware: If you are using drivers other then those that are included in Windows 7 (or 2008 R2), be careful.

Specific examples. Consider them anecdotal but if you run any software mentioned here, or similar software, this list should give you a guide to test.

Users with old versions of Microsoft Security Essentials may not be able to install SP1. Upgrade first.

Samsung Galaxy S phone drivers may have problems with SP1

some users reported very long install times (> 1hr. but not all that unusual for a service pack)

Chrome 10 and 11 have issues according to some tweets

Word 2003 VBA

slower boot times with SP1 then without

some reports of download issues due to overloaded servers

Lenovo's Thinkvantage System Update may not work (update it before applying the SP)